Energy securityPhysics-Based Instruction Leads to Success for Geothermal Drilling
Using the earth’s subsurface heat to change water to steam and power generators to produce electricity is not a new idea. The first large-scale geothermal electricity-generating plant opened in the U.S. in 1960 and has grown to become the most significant energy complex of its kind in the world. But while advances in technology have improved energy production efficiency, one aspect of tapping this renewable resource is still highly cost-prohibitive to those wanting to invest in it: Drilling into the earth.
Researchers Sam Noynaert and Fred Dupriest have been working on a project funded by a $1.86 million grant from the Department of Energy (DOE) to change geothermal drilling practices. Their goals are to refine drilling methods and create a cost-saving business model for future geothermal energy companies.
“One of the DOE’s goals is to make geothermal energy more economical,” said Noynaert, a professor of practice in the Harold Vance Department of Petroleum Engineering at Texas A&M University. “It’s a very low-margin business, so reducing costs has a tangible impact.”
Using the earth’s subsurface heat to change water to steam and power generators to produce electricity is not a new idea, but it’s a proven one. For instance, the first large-scale geothermal electricity-generating plant opened in the U.S. in 1960 and has grown to become the most significant energy complex of its kind in the world. Unfortunately, while advances in technology have improved energy production efficiency, one aspect of tapping this renewable resource is still highly cost-prohibitive to those wanting to invest in it: drilling into the earth.
Every day a rig is in operation requires a great deal of money. Costs stem from the drilling rigs themselves to the many onsite service companies providing personnel and equipment. Therefore, drilling teams that are efficient with both time and money while delivering high-quality, properly placed wellbores are highly valued.
Geothermal wells aren’t drilled frequently. For example, only 15 or 20 wells might be completed in the U.S. per year, with individual companies only drilling one or two. These low numbers mean geothermal drillers can fall behind on best drilling practices, increasing their time and costs because they aren’t constantly on a rig.
Oil and gas drilling, generally done on a nearly continuous basis, has an advantage by improving drilling skills and speed through practice. Yet, this does not mean the best improvements happen. In the late 1990s, only a few companies applied physics-based drilling practices. They collected data on the limiting factors of specific techniques and investigated ways to improve methods and technology. But the industry, as a whole, didn’t apply these practices.
